2 - Air Flashcards
Flight (FLT) DECK FAN Switch - ON
packs off/on
- with all packs off, recirculated cabin air supplied to flight deck
- with at least one pack on, fan increases flow of conditioned air supplied to flight deck
- fan enabled in flight when windshield air is on.
TRIM AIR Switch - ON (what does it do)
master trim air valve open and flight deck, upper deck, and main deck zone trim air valves operate automatically
TRIM AIR Switch - OFF (5)
- master trim air valve closed
- pack output temperature in backup mode regulated to provide average flight deck temperature from 65°F (18°C) to 85°F (29°C) as selected by Flight Deck Temperature selector in AUTO
- cabin temperature panel control of upper deck zone temperatures inhibited
- pack controller A selected and both automatic and manual selection of pack controller B inhibited
- if pack controller A failed, pack controller B selected automatically
Equipment (EQUIP) COOLING Selector - STBY (3)
- ground exhaust valve closed
- automatic control bypassed to configure system for flight; inboard exhaust valve open
- with a single internal fault, equipment inboard exhaust valve closes and cooling system reconfigures to allow internal closed loop recirculation of cooling air
Equipment (EQUIP) COOLING Selector - NORM (3)
- ground operation based on ambient temperature, equipment cooling air exhausted overboard, or exhausted into forward cargo compartment
- with two or more engines running cooling air exhausted into forward cargo compartment and ground exhaust valve closed or inboard exhaust valve closed and equipment cooling air recirculated in a closed loop mode
- with a single internal fault, equipment inboard exhaust valve closes and cooling system reconfigures to allow internal closed loop recirculation of cooling air
Equipment (EQUIP) COOLING Selector - OVRD (4)
- inboard exhaust valve closed
- ground exhaust valve closed
- equipment supply valve closed; cooling air supplied through flight panels
- smoke/override valve open; differential pressure exhausts cooling air overboard
High (HI) FLOW Switch - ON
- all operating packs configured to high flow
* EICAS memo message PACKS HIGH FLOW displays
AFT CARGO Heat (HT) Switch - ON (3)
- overheat shutoff valve opens to provide bleed air heat to aft and bulk cargo compartments
- overheat shutoff valve opens and closes for overheat protection
- temperature control valve opens and closes to maintain temperature
Aft Cargo Temperature (TEMP) Light
- compartment temperature excessive
* overheat shutoff valve closes
PACK Reset (RST) Switch - push
- resets pack fault protection system
* restarts pack after automatic shutdown if fault no longer exists
Pack System (SYS) FAULT Light
• pack overheat or other system fault has occurred
may illuminate briefly when automatically or manually switching from pack temperature controller A to B or B to A
PACKS Control Selectors - NORM
- pack controller A or B selected automatically on alternate flights
- selected controller is primary controller; selects secondary controller if primary controller fails
On the ground, with the engines not operating, the Equipment Cooling selector in NORM, and ambient temperatures moderate or high, the warm exhaust air is _____
With lower ambient temperatures _____
ducted overboard through the ground exhaust valve.
the ground exhaust valve is closed and the inboard exhaust valve opens. The warm equipment cooling
exhaust air discharges into the forward cargo compartment (the system is configured for flight)
There are __ temperature zones:
six • flight deck • upper deck • forward and aft main deck • forward and aft lower lobe cargo zones
The packs are controlled by __ identical pack temperature controllers (PTCs)
two, (A and B)
Control of the packs switches automatically to the other PTC at touchdown. If a PTC detects a fault in a pack channel, control of the respective pack switches to the other PTC
Each PTC has __ separate channels
three, (one for each pack)
If a PTC detects a fault in a pack channel, control of the respective pack switches to the other PTC
Each pack valve has __ flow rates
two, (normal and high)
During cruise, normal flow minimizes bleed air demand on the engine to reduce fuel consumption
Aft cargo heat is provided by bleed air from the ____ bleed air duct
center
Shoulder and foot heat is available ____
in flight
On the ground, with the engines not operating, the Equipment Cooling selector in NORM, and ambient temperatures moderate or high, the warm exhaust air is ____
With lower ambient temperatures ____
ducted overboard through the ground exhaust valve.
the ground exhaust valve is closed and the warm exhaust air is ducted into the forward cargo
compartment (system is configured for flight)
On the ground, when ____ the system
configures for flight.
one or more engines on each wing are operating
Positioning the Equipment Cooling selector to STBY ____
closes the ground exhaust valve to manually configure the airplane for flight
With the Equipment Cooling selector in NORM or STBY, the system normally
configures to ____ if a single internal fan fails.
closed loop mode
In closed loop mode, the inboard exhaust valve is closed
With _____ operating, the flight deck equipment cooling source valve directs conditioned air into the flight deck electrical equipment
two or three packs
The equipment cooling system provides cooling air for flight deck equipment and the electrical and electronic (E &E) compartment equipment racks.
With the Equipment Cooling selector in NORM, the airplane on the ground, and _____, the EICAS alert message _____ is displayed if the equipment cooling system is not configured for flight
one or more engines on each wing operating
EQUIP COOLING
With the Equipment Cooling selector in ____, the internal fans are not powered and the _______ opens with all other valves closed.
OVRD
smoke/override valve
The smoke/override valve opens to an overboard vent allowing ________ to draw air from the panels area on the flight deck, through the equipment cooling ducts to the E &E compartment equipment racks, to create a _______ of air across the equipment, then through the supply duct, and overboard
cabin differential pressure
reverse flow
___ outflow valves are installed at ____ of the cabin.
Two
the rear
The valves normally operate in parallel. Cabin altitude and full ventilation rates can be maintained by either valve
There are ___ cabin altitude controllers
two (A and B)
Each controller controls both outflow valves
maximum cabin altitude is _____
8,000 ft
At touchdown, the outflow valves ____ to ____ the cabin
open
depressurize
The cabin altitude limiter closes both outflow valves if cabin altitude exceeds
11,000 ft
___ mechanical positive pressure relief valves located ____ prevent overpressurization of the airplane.
Two
on the left side of the fuselage
Pack two shuts down to assist in relieving excess cabin pressure
Negative pressure relief valves located _____ open when the airplane cabin pressure is slightly less than outside air pressure.
in the side cargo door and the forward and aft cargo doors
The valves also open to relieve any existing differential pressure when a cargo door is unlatched
Bleed air can be supplied by? (3)
engines
APU
ground air source
Bleed air is used for: (9/10)
• air conditioning • pressurization • wing and engine anti–ice • engine start • leading edge flaps • aft cargo heat • hydraulic reservoir pressurization • potable water tank pressurization • air driven hydraulic demand pumps • thrust reversers
Engine bleed air is supplied from either the ___ or ___ engine sections.
IP or HP
IP air is used during high power setting operations. HP air is used during descent and other low power setting operations
To prevent damage to ducting and equipment downstream, the ___ limits bleed air pressure.
PRV (Pressure Regulating Valve)
The fan air precooler regulates bleed air temperature
During engine start, the engine bleed air valve opens and allows ____ of air from the bleed air duct to open the start valve. The ____ is positively closed to prevent reverse air flow into the engine compressor sections. Any time the engine start valve is not fully closed, the ____ remains positively closed
reverse flow
PRV
PRV
After N2 increases past ____, the start valve closes which enables the ____ to open
50%
PRV
If the engine start valve fails to close, bleed air is isolated from the engine starter because both the ____ and the ____ remain closed.
PRV
engine bleed air valve
Nacelle anti-ice is not available for the respective engine
If an Engine Bleed Air switch is off what 3 valves are closed?
engine bleed air valve
PRV
HP bleed valve
If a bleed air overheat is detected, the ____ and ____ valves close.
PRV and HP bleed
Pushing an Engine Bleed Air switch from off to ON resets the engine bleed fault detection system
Bleed air is available for thrust reverser operation (GE) with the Engine Bleed Air
switch either ON or OFF except when: (3)
- the PRV has failed closed
- the PRV has been closed due a bleed air overheat
- the start valve is not closed
The EICAS memo message APU RUNNING is displayed when ____
APU N1 is 95% and higher
Bleed duct overheat protection is provided in the APU bleed air system to detect leaks. If the APU shuts down for an overheat, _____
it cannot be restarted
The left and right isolation valves separate the bleed air duct into ___ sections when closed?
3
left, center, right
If the center duct section is isolated ____ and ____ are not available
potable water pressurization
cargo smoke detection
If the left or right duct section is isolated, what happens to the leading edge flaps?
operate electrically in secondary mode
isolated because of duct leak so engine bleeds on that side are switched off
What causes a BLEED EICAS message?
bleed overpressure
PRV or HP bleed valve fail to close
What is powered by bleed air? (10)
• air conditioning • pressurization • wing and engine anti–ice • engine start • leading edge flaps • aft cargo heat • hydraulic reservoir pressurization • potable water tank pressurization • air driven hydraulic demand pumps • thrust reversers
Pressing the Landing Altitude (LDG ALT) Switch displays ____ on Primary EICAS?
Manual -
Auto -
Set automatically from _____
landing altitude - MAN
(the EICAS advisory message LANDING ALTITUDE is displayed)
landing altitude - AUTO
(landing altitude from FMC)
What happens with the Cabin Altitude AUTO Selector in NORM? (2)
- cabin altitude controller A or B selected automatically on alternate flights
- selected controller is the primary controller; selects secondary controller if primary controller fails
Isolation (ISLN) VALVE Light - illuminated means?
isolation valve position disagrees with switch position
With the APU Bleed Air Switch - ON, when does the APU Bleed valve open?
EICAS memo message APU RUNNING displayed
What four things cause the Engine Bleed Air System (SYS) FAULT Lights to illuminate? (4)
- overheat
- overpressure
- HP bleed valve open when commanded closed
- PRV open when commanded closed
What happens with ENGINE BLEED Air Switches - ON? (2)
- engine bleed air valve opens for engine start
* engine bleed air valve, PRV, and HP bleed valve open by system logic when bleed air pressure available
What happens with ENGINE BLEED Air Switches - OFF? (3)
• engine bleed air valve, PRV, and HP bleed valve closed
PRV opens for NAI
PRV and HP valve open for thrust reverse
(unless PRV closed by:)
- prior or present bleed air overheat
- start valve not closed
- HP bleed valve failed open
APU Bleed Air VALVE Light - illuminated
APU bleed air isolation valve position disagrees with switch position
Does the ECS Synoptic Display show actual airflow?
No
Air flow displayed is generated by displayed valve positions, switch positions, and pack status. Actual air flow is not displayed, therefore the display may not represent actual system operation
There are ___ temperature zones?
six
- flight deck
- upper deck
- forward and aft main deck
- forward and aft lower lobe cargo zones
The packs are controlled by ___ identical pack temperature controllers (PTCs)
2
A/B
Each pack temperature controller (PTC) has ___ separate channels, ___ for each pack
3/1
Each pack valve has ___ flow rates ___ and ___
2
normal and high.
( during cruise, normal flow minimizes bleed air demand on the engine to reduce fuel consumption. Fuel consumption is reduced approximately 0.3% for each pack in normal flow)
If both PTCs A and B fail, ____
air conditioning packs continue to operate and the pack overheat protection system continues to operate normally. Pack overheat results in a shut down
What does the Flight Deck Fan do?
on the ground -
in flight -
increases flow of conditioned air to the flight deck when at least one pack is operating and supplies recirculated air to the flight deck when all packs are off
only enabled when windshield air is on
Aft cargo heat is provided by bleed air from the ____ section of the bleed air duct
center
The Aft Cargo Heat switch is normally ____ until ____ to increase ____ available for engine start
off
after engine start
bleed air
Shoulder and foot heat are available only in flight. True/False
True
With the Equipment Cooling selector in NORM or STBY, the system normally
configures to _____ if a single internal fan fails.
closed loop mode
(In closed loop mode,
the inboard exhaust valve is closed)
On the ground, with the engines not operating, the Equipment Cooling selector in NORM, and ambient temperatures moderate or high, the warm exhaust air is ____
With lower ambient temperatures, ____
ducted overboard through the ground exhaust valve.
the ground exhaust valve is closed, air ducted into forward cargo and the system is configured for flight
